This new group was established this year to study macromolecular assemblies and multifunctional and multienzyme complexes using x-ray crystallography. Other areas of interest include cytoskeletal proteins and proteins related to HIV and retroviral infection. Most of our effort has been expended planning renovations of space, purchase of new instrumentation, equipment, and supplies and in the recruitment of new post-doctoral associates. The group will be well equipped and is awaiting delivery of a state-of-the-art automated x-ray data collection system based on Fuji image-plate technology, a VAX computer and computer workstations, and an Evans and Sutherland EVS graphics Workstation. Plans are underway to automate much of the routine wet-lab work, particularly in the areas of protein purification and crystallization. The group is adapting a robotic liquid handler to handle the more tedious aspects of experimental screening for crystallization conditions. Research efforts have primarily involved in the preparation of large amounts of pure proteins and preliminary attempts to crystallize them. These include the following: Human histidyl TRNA synthetase, substrate complexes of mutant tryptophan synthase, other tryptophan biosynthetic enzyme including anthranilate synthase and phosphoribosyl transferase from several bacterial sources, the DNA polymerase from T4 phase, and whole LA viral particles.